Calcium uptake by plant cells - channels and pumps acting in concert

How do plant cells accomplish a net uptake of Ca2+ but keep the membrane po tential under control? Consideration of the voltage dependence of the depol arization-activated calcium channel and hyperpolarization-activated calcium channel types, and two other major transporters in the plasma membrane, th e H+-ATPase and I-K,I-out, suggests that one channel is well suited for bot h nutritive and signalling Ca2+ uptake whereas the other could be limited t o a signalling function.